Influence on the Haze Effect of Si Thin-Film Solar Cell on Multi-Surface Textures of Periodic Honeycomb Glass

Abstract

Double textures were applied to use for multi-junction silicon thin film (Si-TF) solar cells. To improve the longer wavelength, we were formed the microscale periodic honeycomb textured surface on a glass substrate. We achieved the transmittance of 94.26% and found the approximately 52% for haze value. Etched AZO films on the textured glass is crucial role for improving the short-wavelength in Si-TF solar cells. Textured AZO film using a 1% HF solution is suitable for the growth of microcrystalline Si and better light trapping. The transmittance was recorded 80.8% that was 3% higher than that of reference fluorine doped tin oxide (FTO, Asahi-U type) glass. We also achieved for high haze value of 59.8% to enable the light trapping across the entire wavelength region. Using a finite-difference time-domain (FDTD) simulation, we designed a multi-junction Si-TF solar cells with high short-circuit current density of 12.5 mA/cm2. To reduce the plasma damage and surface stress on the μc-Si:H layer during growth, we fabricated an a-Si:H/µc-Si:H tandem cell on a multi-surface textures with a µc-Si:H layer of only 1.5 µm thick and obtained a conversion efficiency of 13.3%. The developed double textures structure and fabrication technique are expected to improve the performance of various multi-junction Si thin-film solar cells.